LIBRARY OF CONGRESS 



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UNITED STATES DEPARTMENT OF AGRICULTURE 

lilJI BULLETIN No. 470 a,, 

Sjayvjy^? Contribution from the States Relations Service 

J\Z&*<$£rU A. C. True, Director 




Washington, D. C. PROFESSIONAL PAPER December 22, 1916 

STUDIES ON THE DIGESTIBILITY OF THE GRAIN 

SORGHUMS. 

By C. F. Langworthy, Chief, and A. D. Holmes, Scientific Assistant, Office of Home 

Economics. 



Page. 

Introduction 1 

Milling the grain sorghums 3 

Cooking tests and the experimental diets 4 

Subjects of the experiments 6 

Methods of procedure 6 

Digestibility of the sorghum meals prepared 

as breads 7 



CONTENTS. 

Page. 



Check experiments with breads made from 
corn and wheat meals 19 

Digestibility of the sorghum meals prepared 
as mushes 22 

Summary and conclusions 29 



INTRODUCTION. 

As the result of many attempts to find crops suitable for cultivation 
in the semiarid regions of the Western States of this country, the non- 
saccharine grain sorghums have been successfully introduced from 
South Africa, where they have for a long time held a prominent 
place as a staple cereal crop. In India, China, and other oriental 
countries the sorghums have been used in both animal and human 
nutrition, oftentimes comprising the major portion of the available 
supply of food suitable for human consumption. As an instance of 
their importance, Lapique * states that the dietary of the Abyssinians 
is essentially a vegetarian one composed largely of durra (Sorghum 
vulgare) . In an exploring expedition through China Meyer 2 observed 
that one of the sorghums, kaoliang, was extensively used for 
human food. In some localities it was prepared as a mush and 
eaten by the very poor coolies with such condiments as gingerroot, 
garlic, and radishes. By people slightly better off this sorghum was 
ground into a meal and made into a bread. In both instances 
Meyer observed that exceptionally large quantities of the grain were 
consumed, making an even more bulky diet than most strictly 

1 Compt. Rend. Soc. Biol. [Paris], g (1893), No. 9, pp. 251-258. 2 Personal communication. 

61396°— Bull. 470—10 1 



Monograph 



2 BULLETIN" 470, U. S. DEPARTMENT OF AGRICULTURE. / r> IP 

vegetarian diets, and he believed accordingly that kaoliang was very 
incompletely utilized by the human system. 

In this country feterita, kafir, dwarf milo, and kaoliang are 
well-known varieties of the grain sorghums which have for some time 
been used primarily as feeding crops for animals, but which in some 
instances have formed a part of the human dietary. The people 
living in those sections of the country where the sorghums have been 
grown have long known that these grains are suitable for use as food, 
and the agricultural press has from time to time reported successful 
attempts to use them for this purpose. Moreover, following the 
introduction of the sorghums into the agriculture of the United 
States, commercial attempts have been made to interest the public 
in these grains for bread making and similar uses. 

Numerous tests of these grains have been made to detennine their 
composition and nutritive value as a feeding crop for animals and, 
in some instances, to learn how they may best be prepared for human 
consumption. Many baking tests, for example, have been made with 
the meal of kafir, which is perhaps the best known of the sorghums, 
to determine whether it can be used more advantageously alone or 
mixed with some other meal in ordinary baking practices. The 
Department of Agriculture 1 has studied the preparation and uses of 
kafir meal, reporting a number of recipes for incorporating it in such 
common foods as bread, doughnuts, cookies, etc. A series of baking 
tests described by Dillon 2 indicates that kafir meal in admixture 
with wheat flour in the proportion of 1 to 1, 1 to 2, or 2 to 1, makes 
a very satisfactory bread. Francis 3 reports analyses comparing the 
composition and food value of feterita, Indian corn, kafir, and 
wheat, and gives recipes for the preparation of bread and similar 
products, using part feterita meal and part wheat flour. He con- 
cludes that feterita resembles corn in composition, having a nutritive 
value of about 90 per cent of that of corn, and suggests, moreover, 
that feterita, being somewhat softer than kafir, should be more 
thoroughly digested. General information and a number of tested 
recipes compiled from various sources are given by Davis 4 regarding 
the value of kafir, feterita, and milo as cereal foods. Summers 5 
reports comparative analyses of feterita and wheat together with 
the results of a series of baking tests. He found that the best bread, 
pancakes, or gems, could be made by using 50 per cent of feterita 
meal and 50 per cent of wheat flour. Similar studies of kaoliang are 
reported by Fromme 6 , who used kaoliang meal in place of kafir meal 
in the recipes reported by the Office of Home Economics. 

» U. S. Dept. Agr., Farmers' Bui. 559 (1913), pp. 6, 7. 

2 Northwest. Miller, 90 (1912),) No. 2, pp. 79, 80. 

■ Oklahoma Sta. CIrc. 27 (1914), pp. 8. 

< Texns Dept. A.gr. Bui. 42(1915), p. 18. 

» Oper. Miller, 20 1 1915), No. 1. pp. 42 it. 

"tJouth Dakota Agr. Expt. Sta. Bui. 158 1 1915), pp. 17<M74. 



D. of D. 
JAN 2 1917 



DIGESTIBILITY OF THE GRAIN SORGHUMS. 3 

The results of these investigations as a whole indicate that while 
it is best to use some wheat flour to make up for the lack of gluten 
in the sorghum meal a fairly large proportion of the meal may be 
satisfactorily used in admixture with wheat flour in the preparation 
of common foods. 

According to Davis 1 it has been noted that dwarf kafir will pop 
like pop corn. Tests made in connection with the work of the depart- 
ment showed that this was true of dwarf kafir and of feterita and 
dwarf milo as well, while kaoliang, it was found, scorched without 
popping. The kafir when popped was tender and of good flavor, 
closely resembling ordinary pop corn in miniature. Fewer kernels of 
feterita and dwarf milo popped, and the taste of these, moreover, 
was comparatively raw and less agreeable than that of the kafir. 
The kaoliang became quite crisp and tender without popping and 
had an agreeable taste. It should be noted in trying to pop the sor- 
ghums that, owing to the small size of the grain, the popper should 
be lined with wire netting to prevent its falling through. In similar 
tests with some of the millets no noticeable success was obtained in 
trying to pop the grains. 

Since a survey of the literature indicates that while digestion exper- 
iments with animals are fairly common, few if any studies with man 
have been reported, it seemed desirable to determine experimentally 
the digestibility of the grain sorghums, preparing them in different 
ways for eating, in order to secure data as to their value in human 

nutrition. 

MILLING THE GRAIN SORGHUMS. 

Realizing that considerable differences in the chemical composition 
of any grain occur as a result of variations in climatic and soil condi- 
tions, an attempt was made to obtain a supply of the different grains 
grown under identically the same conditions, and through the coop- 
eration of the Bureau of Plant Industry standardized grain was 
secured from the cereal field .station at Amarillo, Tex. All the 
grains, including the corn and wheat which were used for comparison, 
were milled in the Bureau of Chemistry, the same mill being used for 
each grain and especial care exercised to secure meals of the same 
fineness. Milled in this way, the product in each case more nearly 
resembled meal than flour; consequently "meal" will be the descrip- 
tive term used throughout this discussion. A record was kept of the 
proportions of the different grains passing through the 16, 20, 40, 70, 
and 109 mesh sieves, but only that portion of the meal which passed 
through the 16-mesh sieve (that is, the size of sieve commonly used 
by the housekeeper) was used in the preparation of the experimental 
diet. The amount of kafir bran retained on the sieve and considered 
too coarse to use in the digestion experiments was about 21 per cent 

i Texas Dept Agr. Bui. 12 (1915;, pp. In. 



4 BULLETIN 470, 17. S. DEPARTMENT OF AGRICULTURE. 

of the total. In the case of the other grain sorghums the values 
were, milo, 19 per cent; feterita, 15 per cent; and kaoliang, 5 per 
cent. That these different proportions of the four meals prepared in 
the same mill should be obtained under similar conditions is most 
likely due to the structure of the grain, for, although the break was 
made in the same way, the different grains did not fracture evenly 
along the same lines. The protein content of the meal, which de- 
pends partly upon the quantity of bran removed in the process of 
milling, was proportionately less in the kafir and milo meals than in 
the others, since more bran was removed from them on the sieve. 

COOKING TESTS AND THE EXPERIMENTAL DIETS. 

Before deciding upon the experimental diet a series of tests was 
undertaken to determine a good method of preparing the sorghum 
meals for eating and also a suitable combination of foods to serve as 
a basal ration in the digestion experiments. Results previously re- 
ported from the Office 1 of Home Economics indicated that dwarf 
kafir requires a more thorough cooking than is customary for Indian 
corn, and that it is often desirable to make a mush of the meal as a 
foundation for other dishes (yeast bread, gingerbread, etc.). In view 
of this experience, a mush was first made of one of the sorghum meals 
(kafir) by cooking 3 cups of meal, 3 cups of water, a little salt, and 
3 tablespoonfuls of lard for a half-hour in a double boiler. The lard 
was simply placed on top of the other ingredients, not mixed with 
them, for it was noted that when the lard melted it floated on top 
and prevented excessive evaporation. Baking powder was then 
beaten into the mush and the bread was baked, but because of the 
lack of gluten in the kafir meal difficulty was experienced in making 
such bread light. The addition of glutinous flours, eggs, milk, or 
other substances containing protein was not desirable, for it was recog- 
nized that the presence of protein from any other source than the 
sorghum grain would complicate the problem of determining the di- 
gestibility of the grain protein. It was found, however, that by the 
above method suitable bread resembling corn bread could be made, 
providing the batter was baked in a very thin layer. Owing to the 
loss of practically all the water originally present the bread was 
extremely dry, hard, and crusty and contained practically no crumb. 
It was used only in the first series of experiments with kafir meal, 
when this sorghum was eaten with a basal ration containing only 
milk, fruit (oranges), and a little sugar to make the diet palatable. 

The experience gained in these and earlier cooking tests made it 
evident that in order to cook the grain sorghums thoroughly a pre- 
liminary softening by boiling is desirable, or else it is necessary to 
have sufficient water present to soften the grain during the baking 

i V. S. Dept. Agr. Farmer's Bui. 559 | L918), pp. < ; , "• 



DIGESTIBILITY OF THE URAJ.N SOKGHUMS. 5 

and to prevent the drying out and hardening of the loaf. In most 
of the digestion experiments with the sorghum breads, accordingly, 
the bread was made by the following recipe, which it will be noted 
contains ginger added to make the bread more palatable: 



SORGHUM BREAD. 



15 cups meal. 

3f teaspoons soda. 

If cups molasses. 



3| teaspoons salt. 

5 tablespoons ginger. 

1 scant cup lard (melted in). 



If quarts hot water (added to above mixture). 

In this series of tests the bread was baked about l 1 hours, without 
prehminary cooking in the double boiler. The loss of water by 
evaporation usually caused it to lose from one-fifth to one-sixth of 
its original weight, but moisture enough remained after the baking to 
give a bread composed almost entirely of crumb and sufficiently 
moist to be palatable. Although the bread contained no glutinous 
material as a binder and tended to crumble when hot, it could easily 
be cut without much crumbling when cold. Six similar lots of 
bread were prepared from dwarf kafir, feterita, dwarf milo, kaoliang, 
corn, and wheat meals, and eaten as a part of a simple mixed diet. 
The basal ration was composed of apple sauce, potatoes, and butter 
and furnished only a small fraction of all the protein in the diet, 
namely, about 20 per cent, which was derived very largely from the 
potatoes. Although theoretically it would have been even better to 
eliminate all protein from the basal ration in order to make possible 
an absolutely direct determination of the digestibility of true grain 
protein, it was not considered practicable to make use of a protein- 
free basal ration in these experiments, as such a diet would not have 
been palatable. 

Since it seemed desirable to determine whether the method of pre- 
paring the meals for eating materially influenced their digestibility, 
experiments were also made with the sorghums cooked in the form 
of a mush. It was found that a satisfactory mush could be pre- 
pared in the usual household way as follows: About 15 cups of meal, 
with salt for seasoning, were mixed with somewhat more boiling 
water than could be absorbed, and this was cooked for three to four 
hours in a double boiler which kept the temperature of the mush 
just below the boiling point for the entire cooking period. The basal 
ration eaten with the mushes in the digestion experiments consisted 
of apple sauce, butter, and a cane-sugar sirup — essentially the same 
ingredients as were used in the experiments with the different kinds 
of bread. By omitting the potatoes from the ration, however, the 
amount of protein from accessory foods was greatly reduced, so that 
98 to 99 per cent of the total protein consumed was supplied by the 
grain protein. 



G BULLETIN 470, U. S. DEPABTMEJNT OF AGRICULTURE. 

SUBJECTS OF THE EXPERIMENTS. 

The seven subjects who assisted in the digestion experiments had 
acquired experience in work of this kind from the tests conducted in 
the Office of Home Economics with animal fats. 1 They were young 
men of medium weight and of good health, capable of following 
instructions carefully, and well informed as to the details and condi- 
tions of the experiments. As usual in work of this kind, they were 
informed that regularity in all of their daily habits was highly desir- 
able. No prescribed hour for eating or regular exercise other than 
that ordinarily obtained in pursuance of their daily routine was 

required. 

METHODS OF PROCEDURE. 

The methods employed closely resembled those tested and found 
satisfactory in the experiments with the fats. In order to obtain a 
uniform product the ingredients of the breads and mushes were thor- 
oughly mixed, and care was taken to maintain a constant temperature 
during the cooking process. In each instance sufficient material was 
prepared at one time to supply all the subjects for the entire test 
period. The quantity of the bread or mush eaten was not restricted 
nor were any of the other components of the diet limited except the 
potato. In the diets of which the latter formed a part it was given 
in restricted quantities, so that the potato protein should not form 
too large a proportion of the total protein content of the diet. 

No attention was paid to the maintenance of nitrogen equilibrium, 
nor were collections and analyses of the urine made to determine 
what percentage of energy, owing to the occurrence of incompletely 
oxidized nitrogen in the urine, was not available. Factors based on 
the results of earlier work were used to estimate indirectly the amount 
of energy actually available to the body. A record of body weights 
was not kept, for the purpose of the investigation was primarily the 
determination of the coefficients of digestibility of the grain sor- 
ghums. The 3-day or 9-meal period was judged to be of sufficient 
duration to permit of accurate analytical results, and since the ration 
was made up to resemble closely the ordinary mixed diet, preliminary 
and final periods were omitted. 

All analyses were made according to the methods outlined by 
the Association of Official Agricultural Chemists. 2 Separation of the 
feces of a test period was accomplished by the use of charcoal taken 
in gelatin capsules with the first meal of the experiment and with the 
first meal succeeding the 3-day period. Samples of the bread and of 
the air-dried feces were analyzed, but the composition of the potato, 
apple sauce, and butter was estimated by comparison with the average 
values of a large number of earlier analyses. 3 Allowances were made 

i U. S. Dept. Agr. Bui. 310 (1915). ^u. S. Dept. Agr., Office Expt. Stas. Bui. 28 (I90fi). 

2 U. S. Dept. Agr., Bur. Chem. Bui. 107 (1912). 



DIGESTIBILITY OF THE GKA1N SORGHUMS. 7 

for changes in the composition of the apples and potatoes taking place 
during the preparation for eating. 

The two common methods for determining the coefficients of diges- 
tibility of any single food contained in a mixed diet are, applying the 
factors obtained in a direct determination of the availability of the 
basal ration (digestion experiments with the basal ration alone), and 
using factors for the digestibility of the basal ration which were 
determined by averaging the results of earlier experimental data. In 
the experiments reported in this paper the latter method was used. 
The digestibility of the bread alone was estimated by assuming the 
following values for the digestibility of the accessory food materials : 
The protein of potatoes, 83 per cent ; the protein of milk and butter, 

97 per cent; the protein of fruit, 85 per cent; the carbohydrate of 
potatoes, 95 per cent ; and the carbohydrate of milk and cane sugar, 

98 per cent. These assumed values are not absolute, but are close 
approximations based on the results of a large amount of reliable 
experimental work. 1 

The method of estimating the digestibility of the bread alone is 
indicated by the following equations : 

[Weight of protein in accessory food materials] X [Percentage of 
undigested protein in each] = [Protein in feces from food other than 
bread. 

[Total protein in feces] — [Protein in feces from food other than 
bread] = [Weight of undigested bread protein.] 

[Weight of protein in bread] — [Weight of undigested bread pro- 
tein] -T- [Weight of protein in bread] = [Estimated percentage of avail- 
ability of bread protein.] This value, and a similarly computed one 
for the digestibility of the bread carbohydrate, are given in the tables 
and are taken as the coefficients of availability of the protein and 
carbohydrate in the grains. Since the quantity of lard used in mak- 
ing the bread was greatly in excess of the fat content of the grain, it 
seemed relatively unimportant to estimate the digestibility of the fat 
of the grain. In view of the fact that the diet contained accessory 
foods supplying considerable quantities of both carbohydrate and 
fat, the digestibility of these constituents from the total diet should 
be approximately the same as has been found for the ordinary mixed 
diet, 2 namely, 97 and 95 per cent. 

DIGESTIBILITY OF THE SORGHUM MEALS PREPARED AS BREADS. 

DIGESTION EXPERIMENTS WITH HARD KAFIR BREAD. 

The first series of tests with kafir bread included seven 3-day 
experiments with four different subjects. The bread formed a part 
of a simple mixed diet containing milk, fruit (oranges), and sugar. 
As noted on page 4, this bread was thin and had thick, hard crusts 

1 Connecticut Storrs Sta. Rpt. 1899, p. 104. & Connecticut Storrs Sta. Rpt. 1901, p. 245. 



8 



BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 



but practically no crumb, and since it proved to be rather brittle and 
tasteless, such bread was not used in the studies with the other sor- 
ghums. The data of the experiments are given in the following 
tables : 

Data of digestion experiments with hard kajir bread in a simple mixed diet containing 

milk. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates." 


Ash. 


Experiment No. 89, subject R. L. S.: 

Kafir bread 


Grams. 

1,447.1 

4,326.8 

333.5 

33.9 


Grams. 

292.0 
3, 764. 3 

289.8 


Grams. 

146.6 

142.8 

2.7 


Grams. 
144.7 
173. 1 

.7 


Grams. 

842.9 

216.3 

38.7 

33.9 


Grams. 
20.9 


Milk 


30.3 


Orange 


1.6 


Sugar 












Total food consumed 


6,141.3 
102.9 


4,346.1 


292.1 

39.9 

252.2 


318.5 

20.4 

298.1 


1,131.8 

26.9 

1,104.9 


52.8 


Feces 


15.7 


Amount utilized 




37.1 










Digestibility of entire ration (per cent). 






86.3 


93.6 


97.6 


70.3 










Estimated digestibility of bread alone 
(per cent) 






76.0 




97.9 














Experiment No. 90, subject I. D. B.: 

Kafir bread 


1, 177. 5 

4,309.3 

1, 289. 4 

201.7 


237.6 
3, 749. 1 
1, 120. 5 


119.3 

142.2 

10.3 


117.7 

172.4 

2.6 


685.9 
215.4 
149.6 
201.7 


17.0 


Milk 


30.2 


Orange 


6.4 


Sugar 














Total food consumed 


6, 977. 9 
161.8 


5, 107. 2 


271.8 

73.2 

198.6 


292.7 

24.6 

268.1 


1, 252. 6 

45.9 

1, 206. 7 


53.6 


Feces 


18.1 


Amount utilized 




35.5 










Digetibility of entire ration (per cent). 






73.1 


91.6 


96.3 


66.2 










Estimated digestibility of bread alone 
(per cent) '. 






43.5 




96.7 














Experiment No. 91, subject W. D.: 

Kafir bread 


914.6 
4, 335. 3 
1, 389. 3 


184.6 
3, 771. 7 
1, 207. 3 


92.6 

143.1 

11.1 


91.5 
173.4 

2.8 


532.7 
216.8 
161.2 


13.2 


Milk 


30.3 


Orange 


6.9 


Sugar 


















Total food consumed 


6, 639. 2 
102.7 


5, 163. 6 


246.8 

38.0 

208.8 


267.7 

20.0 

247.7 


910.7 
28.1 

882. 6 


50.4 


Feces 


16.6 


Amount utilized 




33.8 










Digestibility of entire ration (per cent) . 






84.6 


92.5 


96.9 


67.1 










Estimated digestibility of bread alone 
(per cent) 






65.4 




98.6 














Experiment No. 92, subject E. E. M.: 

Kafir bread 


1, 135. 2 

4,294.0 

1,515.6 

195. 2 


229.1 
3, 735. 8 
1, 317. 1 


115.0 

141.7 

12.1 


113.5 

171.8 

3.0 


661.2 
214.7 
175.8 
195.2 


16.4 


Milk 


30.0 


Orange 


7.6 


Sugar 














Total food consumed 


7, 140. 
124.6 


5, 282. 


268. 8 

57. 

211.8 


288.3 

15.8 

272.5 


1,246.9 

34.5 

1,212.4 


54.0 


Feces 


17.3 


Amount utilized 




36.7 










Digestibility of entire ration (per cent) . 






78.8 


94.5 


97.2 


6S.0 










Estimated digestibility of bread alone 
(per cent) 






55.7 




98.7 














Experiment No. 98, subject I. D. B.: 

Kafir bread 


1,307.3 

4, 305. 3 

1,466.5 

207.8 


164.7 
3,745.6 
1,274.4 


152.9 

142.1 

11.7 


320.3 

172.2 
3.0 


643.2 
215.3 
170.1 
207.8 


26. 2 


Milk 


30. 1 


Orange 


7.3 


Sugar 














Total food consumed 


7,286.9 
181.8 


5, 184. 7 


306.7 

93.2 

213.5 


495.5 

26.2 

469.3 


1,236.4 

43.3 

1,193.1 


63.6 




19.1 


Amount utilized 




44.5 










Digestibility of entire ration (per cent). 






69.6 


94.7 


96.5 


70.0 










Estimated digestibility of bread alone 






43.0 




97. 2 
















DIGESTIBILITY OF THE GRAIN SORGHUMS. 



9 



Data of digestion experiments with hard kajir bread in a simple mixed diet containing 

milk — Continued . 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 99, subject W. D.': 

Kafir bread 


Grams. 

798.3 

4,320.6 

1,459.4 


Grams. 

100.6 

3, 758. 9 

1, 268. 2 


Grams. 

93.4 

142.6 

11.7 


Grams. 
195.6 

172.8 
2.9 


Grams. 
392.7 
216.0 
169.4 


Grams. 
16.0 


Milk 


30.3 


Orange 


7.2 


Sugar 


















Total food consumed 


6, 578. 3 
106.8 


5,127.7 


247.7 

36.5 

211.2 


371.3 

23.0 

348.3 


778.1 

29.3 

748.8 


53.5 


Feces 


18.0 


Amount utilized 




35.5 










Digestibility of entire ration (per cent) . 






85.3 


93.8 


96.2 


66.4 










. Estimated digestibility of bread alone 
(per cent) 






67.5 




97.9 














Experiment No. 100, subject E. E. M.: 
Kafir bread 


1, 032. 6 

4,314.0 

1,471.7 

173.4 


130.1 
3, 753. 2 
1,278.9 


120.8 

142.3 

11.8 


253.0 

172.6 

2.9 


508.0 
215.7 
170.7 
173.4 


20.7 


Milk 


30.2 


Orange 


7.4 


Sugar 














Total food consumed 


6,991.7 
133.3 


5, 162. 2 


274.9 

54.8 

220.1 


428.5 

20.4 

408.1 


1,067.8 

37.8 

1, 030. 


58.3 


Feces 


20.3 


Amount utilized 




38.0 










Digestibility of entire ration (per cent) . 






80.1 


95.2 


96.5 


65.2 










Estimated digestibility of bread alone 
(per cent) 






59.7 




97.5 














Average food consumed per subject 
per day 


2,274.1 


1,684.4 


90.9 


117.3 


363.1 


18.4 







Summary of digestion experiments with hard kafir bread in a simple mixed diet con- 
taining milk. 



Experi- 
ment No. 


Subject. Protein. ^^ 


Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates. 


89 


R. L. S 

I.D.B 


Per cent. 
76.0 
43.5 
65.4 
55.7 
43.0 


Per cent. 
97.9 
96.7 
98.6 
98.7 
97.2 


99 

100 


W. D 


Per cent. 
67.5 

59.7 


Per cent. 
97.9 


90 

91 

92 

98 


E.E.M 

Average 


97.5 


E.E.M 

I.D.B 


58.3 


97.8 



As indicated in the summary table, the average estimated values 
for the digestibility of kafir bread alone were 58.3 per cent for the 
protein and 97.8 per cent for the carbohydrate. The bread supplied 
an average of 40 grams of protein and 203 grams of carbohydrate 
daily. The usual figures for the percentage of digestibility of the 
nutrients of cereals are 85 per cent for protein, 90 per cent for fat, 
and 98 per cent for carbohydrates. 1 On the whole, these experiments 
and those that follow indicate that the carbohydrate of the grain 
sorghums is practically as completely utilized for food as can be 
expected with any cereal product, but that the grain protein is very 
incompletely digested. In the comparative experiments which fol- 
low the bread was prepared by a different recipe. 



61396 c 



i Connecticut Storrs Sta. Rpt. 1899, p. 104. 
Bull. 470—16 2 



10 BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 

DIGESTION EXPERIMENTS WITH SOFTER KAFIR BREAD. 

In the second series of tests with dwarf kafir a gingerbread made 
by the recipe on page 5 was eaten with a basal ration containing 
potatoes, apple sauce, butter, and sugar. Since the ration contained 
no milk, it supplied considerably less protein than was furnished in 
the preceding experiments; and the diet proved so satisfactory that 
bread was made in the same way for use in the tests with the other 
sorghums and in the experiments with corn and wheat meals which 
were made for the purpose of comparison. The data of the experi- 
ments with kafir bread are reported in the following tables: 

Data of digestion experiments with softer kafir bread in a simple mixed diet. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 187, subject D. G. G.: 
Kafir bread 


Grams. 

1, 470. 
917.0 

1,165.0 
351.0 
199.0 


Grams. 
512.1 

687.7 

1,048.5 

38.6 


Grams. 

105.7 

27.5 

3.5 

3.5 


Grams. 
93.5 


Grams. 
719.7 
192.6 
107.2 


Grams. 
39.0 


Potato 


9.2 


Apple sauce 


3.5 
298.4 


2.3 


Butter 


10.5 


Sugar 


199.0 














Total food consumed 


4, 102. 
45.0 


2, 286. 9 


140.2 

19.8 

120.4 


395.4 

4.2 

391.2 


1,218.5 

16.2 

1,202.3 


61.0 


Feces 


4.8 


Amount utilized 




56.2 








Digestibility of entire ration (per cent) 




85.9 


98.9 


98.7 


92.1 










Estimated digestibility of bread alone 
(per cent) 






90.8 




98.7 














Experiment No. 188, subject R. L. S.: 
Kafir bread 


1,191.0 
792.0 

1, 108. 
233.0 
157.0 


414.9 

594. 

997.2 

25.6 


85.6 

23.8 

3.3 

2.3 


75.8 


583.1 
166.3 
101.9 


31.6 


Potato 


7.9 


Apple sauce 


3.3 
198.1 


2.3 


Butter 


7.0 


Sugar 


157.0 














Total food consumed 


3,481.0 
144.0 


2,031.7 


115.0 
62.2 
52.8 


277.2 

14.1 

263.1 


1, 008. 3 

53.2 

955.1 


48.8 


Feces 


14.5 


Amount utilized 




34.3 










Digestibility of entire ration (percent) 






45.9 


94.7 


94.7 


70.3 










Estimated digestibility of bread alone 
(per cent) 






38.0 




94.6 














Experiment No. 189, subject 0. E. S.: 
Kafir bread 


1, 325. 
839.0 

1,113.0 
278.0 
192.0 


461.6 

629.2 

1,001.7 

30.6 


95.3 

25.2 

3.3 

2.8 


84.3 


648.7 
176.2 
102.4 


35.1 


Potato 


S.4 




3.4 

236.3 


2.2 


Butter 


8.3 


Sugar 


192.0 














Total food consumed 


3,747.0 
164.0 


2, 123. 1 


126.6 
6S.3 
58.3 


324.0 

15.7 

308.3 


1,119.3 

64.6 

1,064.7 


54.0 


Feces 


15.4 


Amount utilized 




38. 6 








Digestibility of entire ration (per cent). 






46.0 


95.2 


94.2 


71.5 










Estimated digestibility of bread alone 
(per cent) 






38.2 




93.6 














Experiment No. 190, subject R. F. T.: 
Kafir bread 


1,018.0 
547.0 

1,235.0 
168.0 
179.0 


354. 7 

410.2 

1,111.5 

18.5 


73.2 

16.4 

3.7 

1.7 


64.7 


498. 4 
114.9 
113.6 


27.0 


Potato 


5. 5 


Apple sauce 


3.7 

142.8 


2. 5 


Butter 


.->.() 


Sugar 


179.0 














Total food consumed 


3,147.0 
134.5 


1, 891. 9 


95. 
54.3 
40.7 


211.2 
20.7 

190..-) 


905.9 

45. 

860.9 


40. 


Feces 


li.:, 


Amount utilized 




25.5 


Digestibility of entire rat ion (per cent). 








(ID. 2 


95. 


63.7 


Estimated digestibility of bread alone 
(per cent) '. 






:<7.4 




■).-,. 1 















DIGESTIBILITY OF THE GRAIN SORGHUMS* 



11 



Data of digestion experiments with softer kafir bread in a simple mixed diet — Continued . 





Weight. 


Water. 


Protein. 


Eat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 211, subject D. G. G.- 
Kafir bread 


Grams. 

1, 736. 

1, 008. 

798.0 

330.0 

201.0 


Grams. 

583.3 

756.0 

718.2 

36.3 


Grams. 

139.9 

30.2 

2.4 

3.3 


Grams. 
96.4 


Grams. 

871.8 

211.7 

73.4 


Grams. 
44.6 


Potato 


10.1 


Apple sauce 


2.4 

280.5 


1.6 


Butter 


9.9 


Sugar 


201.0 














Total food consumed 


4,073.0 
135.0 


2, 093. 8 


175.8 

66.2 

109.6 


379.3 

9.8 

369.5 


1,357.9 

33.0 

1,324.9 


66.2 




26.0 


Amount utilized : 




40.2 










Digestibility of entire ration (per cent). 






62.3 


97.4 


97.6 


60.7 










Estimated digestibility of bread alone 
(per cent) 






59.0 




98.7 














Experiment No. 212, subject R. L. S.: 
Kafir bread 


1,354.0 
753.0 

1, 122. 
209.0 
182.0 


454.9 

564.8 

1,009.8 

23.0 


109.1 

22.6 

3.4 

2.1 


75.2 


680.0 
158.1 
103.3 


34.8 


Potato 


7.5 


Apple sauce 


3.4 
177.6 


2.2 


Butter 


6.3 


Sugar 


182.0 














Total food consumed 


3, 620. 
136.0 


2, 052. 5 


137. 2 
63.0 
74.2 


256.2 

18.1 

238.1 


1, 123. 3 

40.6 

1, 082. 7 


• 50.8 


Feces 


14.3 


Amount utilized 




36.5 










Digestibility of entire ration (per cent) . 






54.1 


92.9 


96.4 


71.9 










Estimated digestibility of bread alone 
(per cent) 






50.5 




97.2 














Experiment No. 213, subject O. E. S.: 
Kafir bread 


1,631.0 
974.0 

1, 145. 
280.0 
227.0 


548.0 

730.5 

1,030.5 

30.8 


131.5 

29.2 
3.4 

2.8 


90.5 


819.1 
204.5 
105.3 


41.9 


Potato 


9.8 


Apple sauce 


3.5 

238.0 


2.3 


Butter 


8.4 




227.0 














Total food consumed 


4,257.0 
193.0 


2,339.8 


166.9 
83.6 
83.3 


332. 

22.5 

309.5 


1,355.9 

66.3 

1,289.6 


62.4 


Feces 


20.6 


Amount utilized 




41.8 










Digestibility of entire ration (per cent). 






49.9 


93.2 


95.1 


67.0 










Estimated digestibility of bread alone 
(per cent) 






44.2 
45.6 




95.0 
385.2 




Average food consumed per subject 
per day 


1, 258. 4 


705. 8 


103.6 


18.2 







Summary of digestion experiments with softer kafir bread in a simple mixed diet. 



Experi- 
ment 
No. 


Subject. 


Protein. 


Carbohy- 
drates. 


Experi- 
ment 
No. 


Subject. 


Protein. 


Carbohy- 
drates. 


187 

188 

189 

190 

211 


D.G. G 

R.L.S 

O.E.S 

R. F. T 

D. G. G 


Per cent. 
90.8 
38.0 
38.2 
37.4 
59.0 


Per cent. 
98.7 
94.6 
93.6 
95.1 
98.7 


212 


R.L. S 

O.E. S 

Average 


Per cent. 
50.5 
44.2 


Per cent. 
97.2 
95.0 


51.2 


96.1 



In these experiments with the softer kafir bread in a simple mixed 
diet it will be noted that on an average 45.6 grams of protein and 
385 grams of carbohydrate were supplied the subjects daily. The 
bread alone furnished 35 grams and 230 grams of these constituents, 
which were found to be 51.2 per cent and 96.1 per cent digested, 
respectively. These figures indicate that the bread protein appar- 
ently was less available than in the preceding tests in which harde 
kafir bread was eaten with milk. 



12 



BULLETIN 470, V. S. DEPARTMENT OF AGRICULTURE. 



DIGESTION EXPERIMENTS WITH FETERITA BREAD. 

Feterita was also used in the form of a bread flavored with ginger, 
experience having shown that all such gingerbreads, owing to their 
slightly sweet and spicy flavor, are very appetizing. For example, 
the subjects ate an average of eight-tenths of a pound of the feterita 
bread per day and over a pound of the kafir bread which was made 
according to the same recipe. The data of the digestion experiments 
with feterita bread eaten with a simple mixed diet follow: 

Data of digestion experiments with feterita bread in a simple mixed diet. 





"Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 195, subject D. G. G.: 
Feterita bread 


Grams. 

1,422.0 
918.0 
888.0 
268.0 
137.0 


Grams. 

477.9 

688.5 

799.2 

29.5 


Grams. 

113.4 

27.5 

2.7 

2.7 


Grams. 
82.2 


Grams. 

705.6 

192.8 

81.7 


Grams. 
42.9 


Potato 


9.2 


Apple sauce 


2.6 
227.8 


1.8 


Butter 


8.0 


Sugar 


137.0 














Total food consumed 


3, 633. 
124.0 


1,995.1 


146.3 
62.2 
84.1 


312.6 
14.5 

298.1 


1,117.1 

34.9 

1,082.2 


61.9 


Feces 


12 .4 






49.5 










Digestibility of entire ration (per cent). 






57.5 


95.4 


96.9 


80.0 










Estimated digestibility of bread 
alone (per cent) 






52.9 




98.0 














Experiment No. 196, subject P. L. S.: 
Feterita bread 


1,298.0 
728.0 

1,016.0 
208.0 
128.0 


436.3 

546.0 

914.4 

22.9 


103.4 

21.8 

3.1 

2.1 


75.0 


644.1 

152.9 

93.5 


39.2 


Potato 


7.3 


Apple sauce 


3.0 
176.8 


2.0 


Butter 


6.2 


Sugar 


128.0 














Total food consumed 


3,378.0 
106.0 


1,919.6 


130.4 
53.5 
76.9 


254.8 

12.3 

242.5 


1,018.5 

29.4 

989.1 


54.7 


Feces 


10.8 


Amount utilized 




43.9 






» 




Digestibility of entire ration (per cent). 






59.0 
56.3 


95.2 


97.1 
98.5 


80.3 


Estimated digestibility of bread 
alone (per cent) 


















Experiment No. 197, subject 0. E. S.: 
Feterita bread 


993.0 
702.0 
941.0 
204.0 
193.0 


333.8 

526.5 

846.9 

22.4 


79.1 

21.1 

2.8 

2.1 


57.4 


492.7 

147. 4 

86.6 


30.0 


Potato 


7.0 


Apple sauce 


2.8 
173.4 


1.9 


Butter 


6.1 


Sugar 


193.0 












Total food consumed 


3,033.0 
110.0 


1,729.6 


105.1 
52.9 
52.2 


233. 6 

12.3 

221.3 


919.7 
32.6 

887.1 


45.0 


Feces 


12.2 


Amount utilized 




32.8 










Digestibility of entire ration (per cent) . 






49.7 


94.7 


96.5 


72.9 










Estimated digestibility of bread 
alone (per cent) 


' 




43.1 




97.4 














Experiment No. 198, subject R. F. T.: 
Feterita bread 


856.0 
415.0 
1,018.0 
142.0 
178.0 


2S7. 7 

311.2 

916.2 

15.6 


68.2 

12.5 

3.1 

1.4 


49.5 


424.8 
87.1 
93.7 


25. 8 


Potato 


4.2 


Apple sauce 


3.0 
120.7 


2.0 


Butter 


4.3 


Sugar 


178.0 














Total food consumed 


2,609.0 
74.0 


1,530.7 


85.2 
29.7 
55.5 


173. 2 

11.4 

161. 8 


783.6 

23.5 

760.1 


36. :i 


Feces 


9.4 


Amount utilized 




26.9 










Digestibility of entire ration (per cent). 






65.1 


93.4 


97.0 


74. 1 










Estimated digestibility oi bread 






66. 3 




98. 6 















DIGESTIBTLITY OF THE GRAIN SORGHUMS. 13 

Data of digestion experiments with feterita bread in a simple mixed diet — Continued. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 203, subject D. G. G.: 
Feterita bread 


Grams. 

1,205.0 
965.0 
805.0 
306.0 
165.0 


Grams. 

35.0 
723.7 
724.5 

33.6 


Grams. 

105.4 

29.0 

2.4 

3.1 


Grams. 
68.0 


Grams. 

620.3 

202.7 

74.1 


Grams. 
36 3 


Potato 


9 6 


Apple sauce 


2.4 
260.1 


1 6 


Butter 


9.2 


Sugar " 


165.0 














Total food consumed 


3,446.0 
157.0 


1,856.8 


139.9 
81.6 
58.3 


330.5 

11.3 

319.2 


1,062.1 

50.6 

1,011.5 


56 7 


Feces 


13 5 


Amount utilized 




43 2 











Digestibility of entire ration (per cent). 






41.7 


96.6 


95.2 


76 ' ? 










Estimated digestibility of bread alone 
(per cent) 






30.7 




95.2 














Experiment No. 204, subject R. L. S.: 
Feterita bread 


1,298.0 
913. 
888.0 
226.0 
139.0 


403.9 

684.8 

799.2 

24.8 


113.6 

27.4 

2.6 

2.3 


73.2 


668.2 

191.7 

81.7 


39 1 


Potato 


9 1 


Apple sauce 


2.7 
192.1 


1.8 


Butter 


6.8 


Sugar 


139.0 














Total food consumed 


3,464.0 
94.0 


1,912.7 


145.9 
46.8 
99.1 


268. 

8.0 

260.0 


1,080.6 

29.8 

1,050.8 


56.8 


Feces 


9.4 


Amount utilized 




47.4 










Digestibility of entire ration (per cent) . 






67.9 


97.0 


97.2 


83 5 










Estimated digestibility of bread alone 
(per cent) 






66.5 




98.6 














Experiment No. 205, subject 0. E. S.: 
Feterita bread 


876.0 
836.0 
827.0 
182.0 
199.0 


272.6 

627.0 

744.3 

20.0 


76.6 

25.1 

2.5 

1.8 


49.4 


451.0 

175.6 

76.1 


26.4 


Potato 


8.3 


Apple sauce 


2.5 

154.7 


1.6 


Butter 


5.5 


Sugar 


199.0 














Total food consumed 


2, 920. 
99.0 


1,663.9 


106.0 
49.1 
56.9 


206.6 

8.6 

198.0 


901.7 
31.2 

870.5 


41.8 


Feces 


10.1 


Amount utilized 




31.7 










Digestibility of entire ration (per cent) . 






53.7 


95.8 


96.5 


75.8 










Estimated digestibility of bread alone 
(per cent) 






46.6 




97.6 














Experiment No. 206, subject R. F. T.: 
Feterita bread 


850.0 
369.0 
782.0 
136.0 
199.0 


264.5 

276.7 

703.8 

14.9 


74.4 

11.1 

2.3 

1.4 


47.9 


437.6 
77.5 
71.9 


25.6 


Potato 


3.7 


Apple sauce 


2.4 
115.6 


1.6 


Butter 


4.1 


Sugar 


199.0 














Total food consumed 


2.336. 
110.0 


1,259.9 


89.2 
48.5 
40.7 


165.9 

12.5 

153.4 


786.0 

36.5 

749.5 


35.0 


Feces 


12.5 


Amount utilized 




22.5 










Digestibility of entire ration (per cent). 






45.6 


92.5 


95.4 


0-4.3 











Estimated digestibility of bread alone 
(per cent) 






42.1 




95.1 














Average food consumed per subject per day 


1,034.1 


577.8 


39.5 


81.0 


319.6 


16.2 



Summary of digestion experiments with feterita bread in a simple mixed diet. 



Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates. 


Experi- 
ment No. 


Subject. 


Protein. 


Carboh}'- 
drates. 


195 

196 

197 

198 

203 


D.G.G 

R.L.S 

O.E.S 

R.F. T 

D.G.G 


Per cent. 
52.9 
56.3 
43.1 
66.3 
30.7 


Per cent. 
98.0 
98.5 
97.4 
98.6 
95.2 


204 

205 

206 


R.L.S 

O.E.S 

R.F.T 


Per cent. 
66.5 
46.6 
42.1 


Per cent. 
98.6 
97.6 
95.1 


50.6 


97.4 



14 



BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 



In the test periods in which feterita bread was eaten, an average 
of 31 grams of protein and 185 grams of carbohydrate was supplied 
daily by the bread, the protein being 50.6 per cent and the carbo- 
hydrate 97.4 per cent digested. As with the other sorghums, 
although the meal was coarse and apparently increased the peris- 
taltic action of the intestine, no physiological disturbances were 
experienced. 

DIGESTION EXPERIMENTS WITH MILO BREAD. 

Milo bread flavored with ginger was used in this series of tests, 
being supplemented by a simple mixed diet like that provided for 
the other experiments of this series. Four subjects assisted in the 
eight digestion experiments, the results of which are recorded in the 
following tables: 

Data of digestion experiments with milo bread in a simple mixed diet. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 171, subject D. G. G.: 
Milo bread 


Grams. 

1,247.0 
743.0 
871.0 
200.0 
252.0 


Grams. 

389. 4 

557.3 

783.9 

22.0 


Grams. 

94.3 

22.3 

2.6 

2.0 


Grams. 
79.2 

2.6 
170.0 


Grams. 

617.9 

156.0 

80.1 


Grams. 
36.2 


Potato 


7.4 


Apple sauce 


1.8 


Butter 


6.0 


Sugar 


252.0 














Total food consumed 


3,313.0 
148. 


1, 752. 6 


121.2 
72.4 
48.8 
40.3 

31.5 


251. 8 
12.2 

239.6 
95.2 


1.136.0 
50.2 

1,085.8 
95.6 

95.5 


51.4 


Feces 


13.2 


Amount utilized 




38.2 


Digestibility of entire ration (per cen t) . 






74.3 


Estimated digestibility of bread alone 
(per cent) 


















Experiment No. 172, subject R. L. S.: 
Milo bread 


1,330.0 
770. 

1, 075. 
213.0 
100.0 


417.2 

582. 

967.5 

23.4 


101.0 

23.3 

3.2 

2.1 


84.8 


694.2 

163.0 

98.9 


38.8 


Potato 




Apple sauce. 


3.2 
181.1 


2.2 


Butter 


6.4 


Sugar 


100.0 














Total food consumed 


3, 500. 
133.0 


1, 990. 1 


129.6 
63.9 
65. 7 
oO. 7 

45.5 


269. 1 
21.5 

247.6 
92.0 


1.056.1 
34.4 

1,021.7 
96.7 

97.9 




Feces 


13.2 


Amount utilized 




41.9 


Digestibility of entire ration (per cent) . 






76.0 


Estimated digestibility of bread alone 
(per cent) 


















Experiment No. 173, subject 0. E. S.: 
Milo bread 


1,256.0 
651.0 
986.0 
226.0 
217.0 


392.2 

488.3 

887. 4 

24.8 


95.0 

19.5 

3.0 

2.3 


79.8 


652.6 

136.7 

90.7 


36.4 


Potato 


6. 5 


Apple sauce 


2.9 
192.1 


2.0 


Butter 


6.8 


Sugar 


217.0 














Total food consumed 


3,336.0 
116.0 


1, 792. 7 


119.8 
55. 7 
64.1 
53.5 

J9.7 


274.8 
10.7 

264.1 
96.1 


1,097.0 
37.9 

1,059.1 
96.5 

97.3 


51.7 


Feces 


11.7 


Amount utilized 




40.0 


Digestibility of entire ration (percent) . 






77. i 


Estimated digestibility of bread alone 
(per cent) 



















Experiment No. 174, subject P. F. T.: 
Milo bread 


1,007.0 
443.0 

1,105.0 
150. 
253. 


314.5 

332.3 

994.5 

16. 5 


76.1 

13.3 

3.3 

1.5 


63.9 


523. 2 

93.0 

101.7 


29.3 


Potato 


4.4 


Apple sauce 


3.3 
127. 5 


2.2 


Butter 


4.5 


Sugar 


253. 














Total food consumed 

Feces 


2, 95S. 
119.0 


1.657.8 


94.2 
51.2 

43.0 
45. 6 

42.3 


194.7 
13.7 

181.0 
93.0 


970.9 
42.4 

928.5 
95. 6 


40.4 
11.7 


Amount utilized 




28.7 


1 >igestlbllity of entire ration (per cent ) . 





71.0 


Estimated digestibility of bread alone 
(percent) ". 










. 




— 





DIGESTIBILITY OF THE GRAIN SORGHUMS. 15 

Data of digestion experiments with milo bread in a simple mixed diet — Continued. 



- 


Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 218, subject D. G. G.: 
Milo bread 


Grams. 

1,745.0 
819.0 

1, 107. 
340.0 
185.0 


Grams. 

573.2 

606.0 

996.3 

37.4 


Grams. 

130.9 

24.6 

3.3 

3.4 


Grams. 
89.3 


Grams. 
902.3 
180.2 
101.9 


Grams. 
49 3 


Potato 


8.2 


Apple sauce 


3.3 
289.0 


2.2 


Butter 


10 2 


Sugar 


185.0 














Total food consumed 


4, 196. 
159.0 


2, 212. 9 


162.2 
81.5 
80.7 


381.6 

11.5 

370.1 


1,369.4 

51.4 

1,318.0 


69.9 


Feces 


14 6 


Amount utilized 




55.3 










Digestibility of entire ration (per cent). 






49.8 


97.0 


96.2 


79.1 










Estimated digestibility of bread alone 
(per cent) 






44.8 




96.8 














Experiment No. 219, subject R. L. S.: 
Milo bread 


1,727.0 
788.0 

1,075.0 
225.0 
110.0 


567.3 

583.1 

967.5 

24.8 


129.5 

23.6 

3.2 

2.2 


88.4 


893.0 

173.4 

98.9 


48.8 


Potato 


7.9 


Apple sauce 


3.2 
191.2 


2.2 


Butter 


6.8 


Sugar 


110.0 














Total food consumed 


3,925.0 
142.0 


2, 142. 7 


158.5 
72.9 
85.6 


282.8 

15.4 

267.4 


1,275.3 

38.8 

1,236.5 


65.7 


Feces 


14.9 


Amount utilized 




50.8 










Digestibility of entire ration (per cent) . 






54.0 


94.6 


97.0 


77.3 










Estimated digestibility of bread alone 
(per cent) 






50.6 




98.0 














Experiment No. 220, subject 0. E. S.: 
Milo bread 


1,855.0 
747.0 

1, 228. 
300.0 
322.0 


609.4 

552.8 

1, 105. 2 

33.0 


139.1 

22.4 

3.7 

3.0 


95.0 


959.2 
164.3 
113.0 


52.3 


Potato 


7.5 


Apple sauce 


3.7 
255.0 


2.4 


Butter 


9.0 


Sugar 


322.0 














Total food consumed 


4, 452. 
216.0 


2,300.4 


168.2 

104.6 

63.6 


353.7 

18.8 

334.9 


1,558.5 

71.8 

1, 486. 7 


71.2 


Feces 


20.8 


Amount utilized 




50.4 










Digestibility of entire ration (per cent) . 






. 37.8 


94.7 


95.4 


70.8 










Estimated digestibility of bread alone 
(per cent) 






31.6 




95.2 














Experiment No. 221, subject R. F. T.: 
Milo bread 


1,435.0 
595.0 

1, 128. 
240.0 
293.0 


471.4 

440.3 

1,015.2 

26.4 


107.6 

17.8 

3.4 

2.4 


73.5 


742.0 
130.9 
103.8 


40.5 


Potato 


6.0 


Apple sauce 


3.4 
204.0 


2.2 


Butter 


7.2 


Sugar 


293.0 














Total food consumed 


3,691.0 
, 205.0 


1,953.3 


131.2 
89.6 
41.6 


280.9 

24.1 

256.8 


1,269.7 

68.4 

1,201.3 


55.9 


Feces 


22.9 


Amount utilized 




33.0 










Digestibility of entire ration (per cent) . 






31.7 


91.4 


94.6 


59.0 










Estimated digestibility of bread alone 
(per cent) 






24.3 




93.9 














Average food consumed per subject per 
day 


1,223.8 


658.5 


45.2 


95.4 


405.5 


19.2 







Summary of digestion experiments with milo bread in a simple mixed diet. 



Experi- 
ment No. 


Subject. Protein. 


Carbohy- 
drates. 


Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates.' 


171 

172....... 

173 

174 

218 


D. G. G 

R. L. S 

O. E. S 

R. F. T 

D. G. G 


Per cent. 
31.5 
45.5 
49.7 
42.3 
44.8 


Per cent. 
95.5 
97.9 
97.3 
95.8 
96.8 


219 

220 

221 


R. L. S 

O. E. S 

F. F. T 

Average 


Per cent. 
50.6 
31.6 
24.3 


Per ant. 
98: 
95.2 
93.9 


40.0 


96.3 



16 



BULLETIN 470, CJ. S. DEPARTMENT OF AGRICULTURE. 



In the diet containing large quantities of milo bread, the bread sup- 
plied an average of 36 grams of protein and 251 grams of carbohydrate, 
which were estimated to be 40.0 per cent and 96.3 per cent digested, 
respectively. In these experiments, as in the tests with the other 
sorghums, owing to the low protein content of the grains, it would 
have been very difficult for the subjects to eat a sufficient bulk of the 
diet to obtain the amount of protein specified in the common dietary 
standards, namely, 100 grams per man of average weight daily. 

DIGESTION EXPERIMENTS WITH KAOLIANG BREAD. 

Kaoliang bread, or, perhaps better, gingerbread (also flavored with 
ginger), was very similar in taste and appearance to the other sorghum 
breads. Indeed, all the sorghum gingerbreads so clearly resembled 
one another that the subjects apparently believed that they were all 
prepared from the same meal. The essential data of the digestion 
experiments with four subjects are reported as follows: 

Data of digestion experiments with kaoliang bread in a simple mixed diet. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 378, subject D. G. G.: 


Grams. 
1,419.0 

632.0 
1,045.0 

374.0 
94.0 


Grams. 

203.6 

474.0 

914.4 

41.2 


Grams. 

134.8 

19.0 

3.3 

3.7 


Grams. 
124.9 


Grams. 
920.4 
132.7 
120.5 


Grams. 
35.3 




6.3 




4.3 
317.9 


2.5 




11.2 




94.0 














Total food consumed 


3,564.0 
194.0 


1,633.2 


160.8 

102.5 

58.3 


447.1 

22.5 

424.6 


1,267.6 

53.6 

1,214.0 


55.3 


Feces 


15.4 






39.9 










Digestibility of entire ration (per cent) 






36.3 


95.0 


95.8 


72.2 










Estimated digestibility of bread alone (per 






26.8 




96.4 














Experiment No. 379, subject A. J. H.: 
Kaoliang bread 


1,323.0 

599.0 

947.0 

337.0 

44.0 


189.9 

449.2 

828.6 

37.1 


125.7 

18.0 
3.0 
3.4 


116.4 


858.1 
125.8 
109.2 


32.9 


Potato 


6.0 


Apple sauce 


3.9 
286.4 


2.3 


Butter 


10.1 


Sugar . 


44.0 














Total food consumed 


3,250.0 
213.0 


1,504.8 


150.1 

109.0 

41.1 


406.7 

34.6 

372.1 


1, 137. 1 
4& 3 

1,08a 8 


5L3 


Feces 


21.1 






30.2 










Digestibility of entire ration (per cent) 






27.4 


91.5 


95.8 


sa 9 










Estimated digestibility of bread alone (per 
cent) . 






16.1 




96.5 














Experiment No. 380, subject R. L. S.: 
Kaoliang bread 


1,431.0 
587.0 

1,073.0 
270.0 
121. 


205.4 

440.2 

938. 9 

29.7 


135.9 

17.6 

3.4 

2.7 


125. 9 


92a 2 

123.3 
123.7 


35. 6 


Potato 


5.9 


Apple sauce 


4.4 
229.5 


2.6 


Butter 


ai 


Sugar 


121.0 














Total food consumed 


3,482.0 
235.0 


1,614.2 


159.6 

119.1 

40.5 


359. 8 

30.3 

329.5 


1,296.2 

04. 

1, 232. 2 


52.2 


Feces 


21. 6 


Amount utilized 




30.6 










Digestibility of entire ration (per cent) 






25.4 


91.6 


95.0 


5& <! 










Estimated digestibility of bread alone (per 






15.0 




It.-.. 1 















DIGESTIBILITY OF THE GRAIN SORGHUMS. 17 

Data of digestion experiments with kaoliang bread in a simple mixed diet — Continued. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 381, subject 0. E. S.: 
Kaoliang bread ... 


Grams. 

1,228.0 
563.0 

1,002.0 
257.0 
183.0 


Grams. 

176.2 

422.3 

876.8 

28.3 


Grams. 

116.6 

16.9 

3.2 

2.6 


Grams. 
108.1 


Grams. 
796.5 
118.2 
115.5 


Grams. 
30 6 


Potato 


5 6 


Apple sauce 


4.1 

21&4 


2.4 


Butter 


7 7 


Sugar 


183.0 














Total food consumed 


3,233.0 
156.0 


1,503.6 


139.3 

80.5 
58.8 


330.6 

19.2 

311.4 


1,213.2 

41.5 

1, 171. 7 


46 3 


Feces 


14 8 


Amount utilized 




31 5 










Digestibility of entire ration (per cent) 




42.2 


94.2 


96.6 


68 










Estimated digestibility of bread alone (per 
cent) 






34.0 




97.5 












Experiment No. 393, subject D. G. G.: 
Kaoliang bread 


1,828.0 
699.0 
912.0 
385.0 
167.0 


496.7 

527.7 

821.9 

42-3 


139.3 

17.5 

2.4 

3.8 


147.5 

.7 

2.9 

327. 3 


1,008.0 

146.1 

83.1 


36 5 


Potato 


7 


Apple sauce 


1 7 


Butter 


11 6 




167.0 














Total food consumed 


3.991.0 
241.0 


1, 888. 6 


163.0 

126.1 

36.9 


478. 1 

23.2 

455. 2 


1,404.2 

71.5 

1, 332. 7 


56 8 


Feces 


20 2 


Amount utilized 




36 2 










Digestibility of entire ration (percent). 






22.6 


95.2 


94.9 


64 6 








Estimated digestibility of bread alone 
(per cent) 






12.0 




94.8 














Experiment No. 394, subject A. J. H. : 
Kaoliang bread 


1,458.0 

765.0 

841.0 

244.0 

93.0 


396.1 

577.6 

757.9 

26.9 


111.1 

19.1 
2.2 
2.4 


117.7 

.8 

2.7 

207.4 


803.9 

159. 9 

76.6 


29 2 


Potato 


7 6 


Apple sauce 


1 6 


Butter 


7 3 


Sugar 


93.0 














Total food consumed 


3,401.0 
189.0 


1, 758. 5 


134.8 
97.8 
37.0 


328. 6 

27.6 

301.0 


1, 133. 4 

44.4 

1, 089. 




Feces 


19 4 


m Amount utilized 




26 5 










Digestibility of entire ration (percent) . 






27.4 


91.6 


96.1 


58 










Estimated digestibility of bread alone 
per cent) 






15.2 




96.7 














Experiment No. 395, subject P. L. S.:.. 
Kaoliang bread 


1,483.0 

588.0 

966.0 

297.0 

99.0 


402.9 

443.9 

870.6 

32.7 


113.0 

14.7 

2.5 

3.0 


119.7 

.6 

3.1 

252.4 


817.7 

122.9 

88.0 

99.0 


29 7 


Potato 


5.9 


Apple sauce 


1.8 


Butter 


8 9 


Su?ar 














Total food consumed 


3,433.0 
186.0 


1,750.1 


133.2 
97.9 
35.3 


375. 8 

21.4 

354.4 


1, 127. 6 

47.8 
1.079.8 


46.3 


Feces 


18.9 


Amount utilized 




27.4 










Digestibility of entire ration (per cent) . 






26.5 


94.3 


95.8 


59.2 










Estimated digestibility of bread alone 
(per cent) 






16.0 




96.2 














Experiment No. 396, subject 0. E. S.: 
Kaoliang bread 


1,427.0 
712.0 
946.0 
258.0 
324.0 


387.7 

537.6 

852.5 

28.4 


108.7 

17.8 

2.5 

2.6 


115.2 

.7 

3.0 

219.3 


786.9 

148.8 

86.2 


28.5 


Potato 


7.1 


Apple sauce 


1.8 


Butter 


7.7 


Sugar 


324.0 














Total food consumed 


3, 667. 
171.0 


1,806.2 


131.6 
86.8 
44.8 


338.2 

17.1 

321.1 


1,345.9 

50.1 

1, 295. 8 


45.1 


Feces 


17.0 


Amount utilized 




28.1 










Digestibility of entire ration (per cent) . 






34.0 


94.0 


96.3 


62.3 










Estimated digestibility of bread alone 
(per cent) 






23.4 




96.5 














Average food consumed per subject 
per day 


1, 167. 5 


560.8 


48.8 


127.7 


413.6 


lti. 6 







18 BULLETIN 470, IT. S. DEPARTMENT OF AG1UCULTUBE. 

Summary of digestion experiments with laoliang hrcad'in a simple mixed diet. 



Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates. 


£ Subject 


Protein. 


Carbohy- 
drates. 


378 


I). G. G 

A. J. II 

R. L. S 

E S 


Per cent. 
26.8 
16.1 
15.0 
34.0 
12.0 


Per cent. 
96.4 
96.5 
95.4 
97.5 
94.8 


394 

395 

396 


A. J. H 


Per cent. 
15.2 
16.0 
23.4 


Per cent. 
96.7 


379 

380 

381 

393 


R. L. S 

0. E. S 


96.2 
96.5 


D. G. G 




Average 


19.8 


96.3 



In the experiments with kaoliang, notwithstanding the fact that 
the subjects ate nearly a pound of this bread daily, it supplied on 
an average only 41 grams of protein and 288 grams of carbohydrate 
per man per day. As the data recorded above show, the bread pro- 
tein was found to be only 19.8 per cent available to the body, while 
the digestibility of carbohydrate proved to be 96.3 per cent. 

SUMMARY OF DATA ON THE DIGESTffiHJTY OF THE GRAIN-SORGHUM BREADS. 

Considering the experiments with the sorghum gingerbreads as a 
whole, the digestibility of the protein of bread alone averaged less 
than 50 per cent, while that of the carbohydrate constituent of the 
bread was found to be uniformly high. That the digestibility of the 
carbohydrate from the sorghum meals alone is practically identical 
with that of the breads alone is evident from the fact that the only 
accessory carbohydrate present in the breads was a relatively small 
quantity of molasses — a carbohydrate whose digestibility is 98 per 
cent. Moreover the averages for the digestibility of carbohydrate 
from kanr, feterita, milo, and kaoliang breads are practically iden- 
tical with the value usually given for the average simple mixed diet — 
namely, 97 per cent. 1 The close agreement of these values is of 
particular interest, for it indicates that the low values obtained for 
the digestibility of protein are not due to errors in the collections of 
the feces. 

The subjects reported as a rule that they seemed to be in normal 
condition throughout the experimental periods. The diets contain- 
ing the grain sorghums seemed to assist materially the peristaltic 
action of the intestine — an effect which was probably due to the 
large bulk of unassimilated material which the sorghum meals sup- 
ply. In one or two instances the subjects reported sensations of 
hunger and nervous headache, but this was probably due to the fact 
that too little nutritive material was eaten to supply the body needs. 

It is thought that sufficient experimental data have been accumu- 
lated in this series of experiments to permit of an accurate compari- 
son of the digestibility of the sorghums one with another. In order 
to ascertain their digestibility as compared with other cereals, a series 
of check experiments has been made with corn and wheat meal pre- 
pared in the same way and eaten with the same basal ration. 

Connecticut Storrs Sta. Rpt. 1901, p. 245. 



DIGESTIBILITY OF THE GKA1N SORGHUMS. 



19 



CHECK EXPERIMENTS WITH BREADS MADE FROM CORN AND 

WHEAT MEALS. 

The corn and wheat breads used in the following tests were pre- 
pared in the same way as the sorghum gingerbreads (p. 5) and were 
eaten with the same basal ration of apple sauce, potatoes, and but- 
ter. To make certain that the results of these tests should be di- 
rectly comparable with those of the preceding experiments, the details 
of the daily routine and all other conditions essential to accurate work 
were made to correspond nearly exactly. It is to be especially noted 
that the corn and wheat meals used to make the bread were ground 
in the same mill as were the sorghum grains and to the same degree 
of fineness. Such a precaution was necessary in order to remove ap- 
proximately the same percentage of bran from all of the grains. 

Seven digestion experiments, each of the customary three days' 
duration, were conducted with the cooperation of four subjects. 
The results of these tests are reported in the following tables : 

Data of digestion experiments with corn bread in a simple mixed diet. 



Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 231, subject, D. G. G.: 
Corn bread 


Grams. 

1,877.0 
581.0 
950.0 
355.0 
175.0 


Grams. 

773.9 

430.0 

855.0 

39.0 


Grams. 

86.7 

17.4 

2.9 

3.5 


Grams. 
89.9 


Grams. 

889.3 

127.8 

87.4 


Grams. 
37.2 


Potato . 


5.8 


Apple sauce 


2.8 
301.8 


1.9 


Butter 


10.7 


Sugar 


175.0 














Total food consumed 


3, 938. 
139.0 


2,097.9 


110.5 
45.5 
65.0 


394.5 

19.2 

375.3 


1,279.5 

62.6 

1,216.9 


55 6 


Feces 


11 7 


Amount utilized 




43.9 










Digestibility of entire ration (per cent) . 






58.8 


95.1 


95.1 


79.0 










Estimated digestibility of bread alone 
(per cent) 






56.3 


„ 


95.1 














Experiment No. 232, subject, R. L. S.: 
Corn bread 


1,957.0 
526.0 
834.0 
228.0 
-82.0 


806.9 

389.2 

750.6 

25.1 


90.5 

15.8 

2.5 

2.3 


93.7 


927.2 

115.7 

76.7 


38.7 


Potato 


5.3 


Apple sauce 


2.5 

193.8 


1.7 


Butter 


6.8 


Sugar 


82.0 














Total food consumed 


3,627.0 
101.0 


1,971.8 


111.1 

33.6 
77.5 


290.0 

16.5 

273.5 


1,201.6 

41.5 

1, 160. 1 


52.5 


Feces 


9.4 


Amount utilized 




43.1 










Digestibility of entire ration (per cent) . 






69.8 


94.3 


96.5 


82.1 










Estimated digestibility of bread alone 
(per cent) 






70.1 




97.2 














Experiment No. 233, subject 0. E. S.: 
Corn bread 


2, 129. 
670.0 
849.0 
293.0 
344.0 


877.8 

495.8 

764,1 

32.2 


98.4 

20.1 

2.5 

2.9 


102.0 


1, 008. 7 

147.4 

78.1 


42.1 


Potato 


6.7 


Apple sauce 


2.6 
249.1 


1.7 


Butter 


8.8 


Sugar 


344.0 














Total food consumed 


4, 285. 
148.0 


2,169.9 


123.9 
53.5 
70.4 


353.7 

21.3 

332.4 


1, 578. 2 

60.8 

1,517.4 


59.3 


Feces 


12.4 


Amount utilized 




46.9 










Digestibility of entire ration (per cent). 






56.8 


94.0 


96.1 


79.1 










Estimated digestibility of bread alone 
(per cent) 






53.2 




96.2 














Average food consumed per subject 
per day 


1,316.7 


693.3 


38.4 


115.4 


451.0 


L8.6 







"20 BULLETIN 4*743, U. S. DEPARTMENT OF AGRICULTURE. 

Summary of digestion experiments villi corn bread in a simple mixed diet. 



Experiment No. 




Subject. 


Protein. 


Carbohy- 
drates. 


231 


D. G. G 


_ 


Per cent. 
56.3 
70.1 


Per cent. 
95.1 


232 


R. L. S 




97.2 


233 


O. E. S. 




53.2 j 96.2 




A verage 








59.9 


96.2 



Data of digestion experiments with wheat bread in a simple mixed diet. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 226, subject D. G. G.: 
Wheat bread 


Grams. 

2, 035. 
478.0 
904.0 
307.0 
193.0 


Grams. 

823.4 

353.7 

813.6 

33.8 


Grams. 

155.1 

14.3 

2.7 

3.1 


Grams. 
110.1 


Grams. 

890.2 

105.2 

83.2 

i93.'6" 


Grams. 
56.2 


Potato 


4.8 


Apple sauce 


2.7 
260.9 


1.8 


Butter 


9.2 


Sugar 






i 






Total food consumed 


3,917.0 
153.0 


2, 024. 5 


175.2 

48.4 
126.8 


373.7 

13.7 

360.0 


1,271.6 

74.7 

1,196.9 


72.0 


Feces 


16.2 


Amount utilized . 




55.8 










Digestibility of entire ration (per cent) . 






72.4 


96.3 


94.1 


77.5 











Estimated digestibility of bread alone 
(per cent) 








73.0 




93.6 














Experiment No. 227, subject R. L. S.: 
Wheat bread 


. 
1,807.0 
509.0 
909.0 
192.0 
121.0 


731.0 

376.6 

818.1 

21.1 




137.8 
15.3 

2.7 
1.9 


97.8 


790.5 

112.0 

83.7 


49.9 


Potato 


5.1 


Apple sauce 


2.7 
163.2 


1.8 


Butter 


5.8 


Sugar 


121.0 














Total food consumed 


3, 538. 
71.0 


1,946.8 


157.7 

22.1 

135.6 


263.7 

9.1 

254.6 


1, 107. 2 

31.3 

1,075.9 


62.6 


Feces 


8.5 


Amount utilized 





54.1 










Digestibility of entire ration (per cent) . 




86.0 


96.5 


97.2 


86.4 








Estimated digestibility of bread alone 
(per cent) 


1 


88.8 




98.1 






1 






Experiment No. 228, subject 0. E. S.: 
Wheat bread 


2, 137. 
591.0 
880.0 
262.0 
313.0 


864.6 
437.4 
792.0 

28.8 


163. 

17.7 

2.6 

2.6 


115.6 


934.8 

130. 

81.0 


59.0 


Potato 


5.9 


Apple sauce 


2.6 
222.7 


1.8 


Butter 


7.9 


Sugar 


313. 














Total food consumed 


4,183.0 
200.0 


2, 122. 8 


185.9 

61.8 

124.1 


340. 9 

30.5 

310.4 


1,458.8 

84.6 

1,374.2 


74.6 


Feces 


23.1 


Amount utilized 




51.5 










Digestibility of entire ration (per cent). 






66.8 


91.1 


94.2 


69.0 










Estimated digestibility of bread alone 
(per cent) 






66.4 




93.2 














Experiment No. 229, subject R. F. T.: 
Wheat bread 


1,401.0 
346.0 
882.0 
154.0 
220.0 


566.8 

256.0 

793.8 

17.0 


106.8 

10.4 

2.7 

1.5 


75.8 


612.9 
76.1 
81.1 


38.7 


Potato 


3.5 


Apple sauce 


2.6 
130.9 


1.8 


Butter 


4.6 


Sugar 


220.0 














Total food consumed 


3,003.0 
92.0 


1,633.6 


121.4 
26.0 
95.4 


209.3 

15.6 

193. 7 


990.1 

38.2 

951.9 


48.6 


Feces . . 


12.2 


Amount utilized 




36.4 










Digestibility of entire ration (per cent). 






78.6 


92.5 


96.1 


74.9 










Estimated digestibility of bread alone 
(per cent) 






81.0 




96 4 














Average food consumed per subject 
per day 


1,220.1 


644.0 


53.3 


99.0 


402.3 


21.5 







DIGESTIBILITY OF THE GRAIN SORGHUMS. 21 

Summary of digestion experiments with wheat bread in a simple mixed diet. 



Experi- 
ment No. 


Subject. 


Protein. 


Carbo- 
hydrates. 


Experi- 
ment No. 


Subject. 1 Protein. 


Carbo- 
hydrates. 


226 

227 

228 


D.G.G 

R.L.S 

O.E.S 


Per cent. 
73.0 
88.8 
66.4 


Per cent. 
93.6 
98.1 
93.2 


229 


R.F.T 

Average 


Per cent. 
81.0 


Per cent. 
96.4 


77.3 


95.3 



The digestibility of fat and carbohydrate in both the corn and the 
wheat bread diets was very satisfactory, 94.5 per cent of fat and 95.9 
per cent of carbohydrate in the ration containing corn, and 94.3 per 
cent of fat and 95.6 per cent of carbohydrate in the wheat diet 
representing the percentages of available nutrients. The estimated 
value for the digestibility of the carbohydrate of corn bread alone is 
96.6 per cent and of the carbohydrate of wheat bread 95.9 per cent. 

An average of 38.4 grams of protein per man per day was 61.8 per 
cent digested in the experiments with corn bread and, although the 
average daily consumption of protein in the experiments with wheat 
was only 53.3 grams, this was 76.0 per cent available to the body. 
The estimated digestibility of the protein supplied by the corn bread 
alone is 59.9 per cent, and of the protein supplied by wheat bread 
77.3 per cent. These values undoubtedly vary with the quantity of 
bran present in the flour and with other experimental conditions, 
such as the nature of the diet and the quantity of protein eaten. 
This opinion is in accordance with the conclusions of other investi- 
gators. Results of experiments by Woods and Merrill, 1 conducted 
in cooperation with the earlier work of the Omce of Home Economics, 
indicate that all kinds of wheat bread are well digested and deserving 
of the important place given to them in the diet. These investi- 
gators found that the digestibility of the protein of wheat bread 
varied from 93.8 per cent for standard patent to 80 per cent for 
entire wheat flour. Snyder 2 also studied the comparative digesti- 
bility of protein in different grades of wheat flour, finding that 
although the entire wheat and graham flours contained more protein 
than the patent flours, the percentages of protein actually available 
to the body was greater in the patent flour. In experiments with 
Indian corn meal prepared for eating in several different ways, 
Merrill 3 found a digestibility of protein varying from 73 to 86 per 
cent. 

The digestibility of corn protein herein determined, 55.4 per cent, 
is somewhat lower than that usually reported, but it seems reasonable 
to conclude, in comparison with the preceding experiments with the 
grain sorghums in identically the same basal ration, that corn pro tern 
is more thoroughly digested than are the protein constituents of dwarf 

i U. S. Dept. Agr., Office Expt. Sta. Bui. 143 (1904), p. 33. 2 Maine Sta. Bui. 131 (1906). 
• ldem,126 (1903), p. 46: 156 (1905). 



22 



BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 



kafir, feterita, dwarf milo, and kaoliang. As indicated by its digesti- 
bility, 74.4 per cent, wheat protein is even more completely available 
to the body. Since the sorghums contain less protein than is found 
in either corn or wheat, and as these tests indicate that the protein, 
gram for gram, is less thoroughly digested than that of corn and 
wheat, it may be concluded that both corn and wheat contain more 
available protein than do the sorghum grains. 

DIGESTIBILITY OF THE SORGHUM MEALS PREPARED AS MUSHES. 

DIGESTION EXPERIMENTS WITH KAFIR MUSH. 

To ascertain whether or not the method of cooking the sorghum 
meals influences their digestibility, the series of tests reported in the 
following pages was made. In these experiments kafir meal from 
the same lot as that used in the preceding tests was cooked as a mush 
(p. 5) , which was eaten with a basal ration consisting of apple sauce, 
butter, sirup, and sugar. The diet proved entirely satisfactory for 
the tests, in that it was sufficiently appetizing to preclude any psychic 
dislike of the food, so that a nominal quantity of mush was willingly 
eaten. The same subjects cooperated in these tests and continued 
the same routine that was followed in the previous experiments. 

The experimental data of three experiments with kafir mush are 
summarized in the following tables : 

Data of digestion experiments with kafir mush in a simple mixed diet. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 239, subject D. G. G.: 
Kafir mush 


Grams. 
3,299.0 


Grams. 
2, 415. 9 


Grams. 
130.0 


Grams. 
1.3 


Grams. 
698.1 


Grams. 
53.7 


Apple sauce 




Butter 


248.0 

1,617.0 

135.0 


27.3 
681.0 


2.5 


210.8 




7.4 


Sirup 


936.0 
135.0 




Sugar 


















Totai food consumed 


5,299.0 
119.0 


3,124.2 


132.5 
52.9 
79.6 


212.1 

11.4 

200.7 


1, 769. 1 

43.8 
1, 725. 3 


61.1 


Feces 


10.9 


Amount utilized 




5a 2 










Digestibility of entire ration (per cent) . 






60.1 


94.6 


97.5 


82.2 










Estimated digestibility of mush alone 
( per cent) 






59.4 




96.8 














Experiment No. 240, subject R. L. S.: 
Kafir mush 


3, 282. 
437.0 
290.0 

1,315.0 
52.0 


2, 403. 4 

396.8 

31.9 

555. 6 


129.3 
1.0 
2.9 


1.3 

1.3 

246.5 


694.5 
37.1 


53. 5 


Apple sauce 


.8 


Butter 


S. 7 


Sirup 


759.4 
52.0 




Sugar 


















Total food consumed 


5, 376. 
119.0 


3, 387. 7 


133.2 
50.0 
83. 2 


249.1 
17.3 

231. S 


1,543.0 
38.2 

1,504. S 


63.0 


Feces 


13.5 


Amount utilized 




49. 5 










Digestibility of entire ration (per cent). 






62.5 


93. 1 


97.5 


78.6 











Estimated digestibility of mush alone 
(per cent) 






61.5 




97.4 















DIGESTIBILITY OF THE GRAIN SORGHUMS. 23 

Data of digestion experiments with kajir mush in a simple mixed diet — Continued. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 241, subject 0. E. S.: 
Kafir mush 


Grams. 
3,089.0 
1,069.0 
156.0 
1, 580. 
52.0 


Grams. 
2,262.1 

970.6 
17.1 

669.7 


Grams. 

121.7 

2.6 

1.6 


Grams. 

1.2 

3.2 

132.6 


Grams. 

653.6 

90.7 


Grams. 
50.4 


Apple sauce 


1.9 


Butter . 


4.7 


Sirup 


910.3 
52.0 




Sugar 


















Total food consumed 


5, 946. 
196.0 


3,919.5 


125. 9 
93.5 
32.4 


137.0 

17.7 

119.3 


1,706.6 

65.9 

1,640.7 


57.0 


Feces . 


18.9 


\mount utilized 




38.1 










Digestibility of entire ration (per cent) . 






25.7 


87.1 


96.1 


66.8 










Estimated digestibility of mush alone 
(per cent) . 






23.5 
43.5 




94.2 
557.6 




Average food consumed per subject per 
day 


1, 846. 8 


1,159.1 


66.5 


20.1 







Summarij of digestion experiments with kafir mush in a simple mixed diet. 



Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates. 


239 


D.G.G 


Per cent. 
59.4 
61.5 
23. 5 


Per eev'. 
96. 8 


240 


R. L. S 


97.4 


241 


O.E.S 


94.2 




Average 






48.1 


96.1 









The results of the data tabulated above show that, while 96.1 per 
cent of the carbohydrate of kafir mush was digested, an average of 
only 48.1 per cent of the protein was available to the body. It was 
found that the mush supplied 42 grams of protein and 227 grams of 
carbohydrate per man per day. 

DIGESTION EXPERIMENTS WITH FETERITA MUSH. 

Feterita mush prepared in the manner already described formed 
a large part of the diet of the following experiments, and the same 
basal ration, consisting of apple sauce, butter, sirup, and sugar, was 
eaten with the mush. The following tables record the data of the 
digestion experiments. 

Data of digestion experiments with feterita mush in a simple mixed diet. 



Experiment No. 258, subject H. F. B. 

Feterita mush 

Apple sauce 

Butter 

Sirup 

Sugar 



Total food consumed . 

Feces 

Amount utilized 



Digestibility of entire ration (per cent) . 

Estimated digestibility of mush alone 
(per cent) 



Weight. 



Grams. 
2,915.0 
1, 174. 

205.0 
1, 346. 

220.0 



5, 860. 
53.0 



Water. 



Grams. 

1,929.1 

1,066.0 

22.6 

350.0 



3,367.7 



Protein. 



Grams. 

131.2 

2.8 

2.0 



136.0 

29.6 

106.4 



78.2 



Fat. 



Grams. 

8.7 

3.5 

174.3 



186.5 

4.4 

182.1 



97.6 



Carbohy- 
drates . 



Grams. 

803.7 

99.6 



996.0 
220.0 



2,119.3 
- 15.0 
2, 104. 3 



Ash. 



99.3 



99.3 



Grams. 
42.3 
2.1 
6.1 



50.5 

4.0 

46.5 

92.1 



24 BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 

Data of digestion experiments withfeterita mush in a simple mixed diet — Continued. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates'. 


Ash. 


Experiment No. 259, subject D. G. G.: 
Feterita mush 


Grams. 
3,027.0 


Grams. 
2,003.3 


Grams. 
136.2 


Grams. 
9.1 


Grams. 
834.5 


Grams. 
43.9 






Butter 


240.0 

1, 258. 

112.0 


26.4 
327.1 


2.4 


204.0 




7.2 


Sirup 


930.9 
112.0 




Sugar 


















Total food consumed 


4,637.0 
150.0 


2,356.8 


138.6 
76.9 
61.7 


213.1 

16.8 

196.3 


1, 877. 4 

43.3 

1,834.1 


51.1 


Feces 


13.0 


Amount utilized 




38.1 










Digestibility of entire ration (per cent) 






44.5 


92.1 


97.7 


74.6 









Estimated digestibility of mush alone 
(per cent) 






43.6 




97.3 














Experiment No. 260, subject R. L. S.: 
Feterita mush 


2,490.0 
853.0 
203.0 

1, 163. 
33.0 


1,647.9 

774.5 

22.3 

302.4 


112.0 
2.1 

2.0 


7.5 

2.6 

172.6 


686.5 
72.3 


36.1 


Apple sauce 


1.5 


Butter . 


6.1 


Sirup 


860.6 
33.0 




Sugar . 














Total food consumed 


4, 742. 
125.0 


2, 747. 1 


116.1 

64.9 
51.2 


182.7 

12.1 

170.6 


1, 652. 4 

36.8 

1,615.6 


43.7 


Feces 


11.2 


Amount utilized 




32.5 










Digestibility of entire ration (per cent) . 






44.1 


93.4 


97.8 


74.4 










Estimated digestibility of mush alone 






42.1 




98.3 














Experiment No. 261, subject 0. E. S.: 
Feterita mush 


2, 825. 
1, 274. 

135.0 
1,658.0 

166.0 


1,869.6 

1, 156. 8 

14.9 

431.1 


127.1 
3.1 
1.3 


8.5 

3.8 

114.8 


778.8 
108.0 


41.0 


Apple sauce 


2.3 
4.0 


Sugar 


1,226.9 
166.0 




















Total food consumed 


6,058.0 
162.0 


3,472.4 


131.5 

88.5 
43.0 


127.1 

18.8 
108.3 


2, 279. 7 

41.8 

2.237.9 


47.3 


"Feces 


12.9 


Amount utilized 




34.4 










Digestibility of entire ration (per cent) . 






32.7 


85.2 


98.2 


72.7 








Estimated digestibility of mush alone 
(per cent) 






30.4 




99.6 














Average food consumed per subject per 


1,774.7 


995.3 

1 


43.5 


59.1 


660. 7 


16.1 



Summary of digestion experiments withfeterita mush in a simple mixed diet. 



Experi- 
ment No. 


Subject. 


Protein. 


Carbo- 
hydrates. 


Experi- 
ment No. 


Subject. 


Protein. 


Carbo- 
hydrates. 


258 

259 

260 


H. F. B 

D. G. G 

R. L. S 


Per cent. 
77.5 
43.6 
42.1 


Per cent. 
99.3 
97.3 
98.3 


261 


O. E. S 


Per cent. 
30.4 


Per a nt. 

99. 6 




48.4 


98.6 



In these experiments an average of 43.5 grams of protein was 
supplied by the total diet, and of this amount 42.2 grams, or about 
97 per cent was derived from the feterita meal and 48.4 per cent 
digested. The carbohydrate portion of the mush, as in the other 
tests, was very completely utilized, since an average of 259 grams 
daily was 98.6 per cent digested. 



DIGESTIBILITY OP THE GRAIN SORGHUMS. 



25 



DIGESTION EXPERIMENTS WITH MILO MUSH. 

Milo niush closely resembled the other mushes in appearance and 
lack of definite flavor. Eaten with sirup and butter, however, it was 
apparently relished by the four subjects who assisted in the experi- 
ments recorded below: 



Data of digestion experiments with milo mush in a simple mixed diet. 



1 Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates." 


Ash. 


Experiment No. 254, subject H. F. B.: 
Milo mush 


Grams. 
3, 656. 
1,021.0 

277.0 
1,494.0 

209.0 


Grams. 
2,772.0 

927.1 
30.5 

556.0 


Grams. 

121.0 

2.4 

2.8 


Grams. 

25.6 

3.1 

235.4 


Grams. 

690.6 

86.6 


Grams. 
46.8 


Apple sauce 


1.8 


Butter 


8.3 


Sirup 


938.0 
209.0 




Sugar 


















Total food consumed 


6,657.0 
189.0 


4, 285. 6 


126.2 
95.9 
30.3 


264.1 

18.9 

245.2 


1,924.2 

59.2 

1,865.0 


56.9 


Feces 


15.0 


Amount utilized 




41.9 










Digestibility of entire ration (per cent). 






24.0 


92.8 


96.9 


73.6 










Estimated digestibility of mush alone 
(per cent) 






21.2 




96.0 














Experiment No. 255, subject D. G. G.: 
Milo mush 


3,972.0 


3,011.6 


131.5 


27.8 


750.3 


50.8 


Apple sauce 




Butter 


249.0 

1,424.0 

129.0 


27.4 
520.8 


2.5 


211.6 




7.5 


Sirup 


903.2 
129.0 




Sugar 


















Total food consumed 


5,774.0 
151.0 


3,559.8 


134.0 
79.5 
54.5 


239.4 

11.8 

227.6 


1,782.5 

46.0 

1, 736. 5 


58.3 


Feces 


13.7 


Amount utilized 




44.6 










Digestibility of entire ration (per cent). 






40.7 


95.1 


97.4 


76.5 










Estimated digestibility of mush alone 
(per cent) 






39.5 




96.6 














Experiment No. 256, subject R. L. S.: 
Milo mush 


2,945.0 
744.0 
201.0 

1,225.0 
20.0 


2,232.9 

675.6 

22.1 

476.5 


97.5 
1.8 
2.0 


20.6 

2.2 

170.9 


556.3 
63.1 


37.7 


Apple sauce 


1.3 


Butter 


6.0 


Sirup 


748.5 
20.0 




Sugar 


















Total food consumed 


5,135.0 
102.0 


3,407.1 


101.3 
51.9 
49.4 


193.7 

13.2 

180.5 


1,387.9 

26.1 

1,361.8 


45.0 


Feces 


10.8 


Amount utilized 




34.2 










Digestibility of entire ration (per cent). 






48.8 


93.2 


98.1 


76.0 










Estimated digestibility of mush alone 
(per cent) . ... 






47.2 




99.2 


» 












Experiment No. 257, subject 0. E. S.: 
Milo mush 


3,642.0 
1,087.0 

166.0 
1,473.0 

206.0 


2,761.4 

987.0 

18.2 

552.9 


120.5 
2.6 
1.7 


25.5 

3.2 

141.1 


688.0 
92.2 


46.6 


Apple sauce 


2.0 


Butter 


5.0 


Sirup 


920.1 
206.0 




Sugar 


















Total food consumed 


6,574.0 
167.0 


4,319.5 


124.8 
85.3 
39.5 


169.8 

21.8 

148.0 


1,906.3 

45.0 

1,861.3 


53.6 


Feces 


14.9 


Amount utilized 




38.7 










Digestibility of entire ration (per cent). 






31.7 


87.2 


97.6 


72.2 










Estimated digestibility of mush alone 
(per oent) . 






29.6 




98.9 














Average food consumed per subject per 
day 


2,011.7 


1,297.7 


40.5 


72.3 


583. 4 


17. s 







2G BULLETIN 470, L T . S. DEPARTMENT OF AGRICULTURE. 

Summary of digestion experiments with mi to mush in a simple mixed diet. 



Experi- 
ment No. 


Subject . 


Protein. 


Carbohy- 
drates'. 


Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates'. 


254 

255 


H. F.B 

D. G. G 

R. L. S 


Per cent. 
21.2 
39 5 


Per cent. 
96.0 
96 6 


257 


0. E. S 

Average 


Per cent. 
29.6 


Per cent. 
98.9 


256 


47.2 


99.2 


34.4 


97.7 



In the above summary it will be noted that an average of 97.7 per 
cent of the carbohydrates of milo mush was digested and that 34.4 
per cent of the milo protein was assimilated by the body. This mush 
was apparently less digested than that of the preceding experiments 
and, moreover, it supplied only 39 grams of protein and 224 grams 
of carbohydrates daily. 

DIGESTION EXPERIMENTS WITH KAOLIANG MUSH. 

Kaoliang mush was of a light-chocolate color and so had a differ" 
ent appearance from that of the other mushes. Its flavor, however, 
was not pronounced, but much like that of the mushes made from the 
other grain sorghums studied. The essential data of eight diges- 
tion experiments in which four subjects assisted are recorded in the 
following tables : 

Data of digestion experiments with kaoliang mush in a simple mixed diet. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 385, subject D. G. G.: 
Kaoliang mush 


Grams. 
3, 060. 
1,013.0 

267.0 
1,586.0 

129.0 


Grams. 
2, 400. 9 

916.3 
29.4 

634.4 


Grams. 

82.3 

2.5 

2.7 


Grams. 

27.9 

3.2 

226.9 


Grams. 

527. 5 

89.1 


Grams. 
21.4 


Apple sauce 


1.9 


Butter 


8.0 


Sirup 


951.6 
129.0 




Sugar 


















Total food consumed 


6, 055. 
166.0 


3,981.0 


87.5 

85.9 

1.6 


258.0 

19.2 

238.8 


1, 697. 2 

47.1 

1, 650. 1 


31.3 


Feces : 


13.8 


Amount utilized 




17.5 










Digestibility of ent ire ration (per cent). 






18.3 


92.6 


97.2 


55.9 










Estimated digestibility of mush alone 
(per cent) 










96.9 
















Experiment No. 386, subject A. J. H.: 
Kaol iang mush 


2,388.0 

931.0 

164.0 

479.0 

89.0 


1, 873. 6 

842.1 

18.1 

191.6 


64.3 
2.3 
1.6 


21.7 

2.9 

139.4 


411.7 
81.9 


16.7 


Apple sauce 


1.8 


Butter 


4.9 


Sirup 


287. I 
89.0 




Sugar 


















Total food consumed 


4,051.0 
149.0 


2, 925. 4 


68.2 
82.0 


164.0 

21.4 

142.6 


S70. 

32. 1 

837.9 


23-4 


Feces 


13.5 


Amount utilized 




9.9 












Digestibility of entire ration (per cent). 








87.0 


96.3 


42.3 












Estimated digestibility of mush alone 
(per cent) 










96.0 

















DIGESTIBILITY OJP THE (JKAIN SORGHUMS. 27 

Data of digestion experiments with kaoliang mush in a simple mixed diet— Continued . 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 387, subject R. L. S.: 
Kaoliang mush 


Grams. 

2, 849. 

1,024.0 

260.0 

396.0 

46.0 


Grams. 
2, 235. 3 

926.2 
28.6 

158.4 


Grams. 

76.6 

2.6 

2.6 


Grams. 

25.9 

3.2 

221.0 


Grams. 

491.2 

90.1 


Grams. 
20.0 


Apple sauce 


1.9 


Butter 


7.8 


Sirup 


237.6 
46.0 




Sugar 


















Total food consumed 


4, 575. 
155. 


3, 348. 5 


81.8 
85.3 


250. 1 

19.5 

230.6 


864.9 

36.3 

828.6 


29.7 


Feces 


13.9 


Amount utilized 




15.8 






I 




Digestibility of entire ration (per cent) . 








92.2 


95.8 


53.2 






• 




Estimated digestibility of mush alone 
(per cent) 








95.6 














Experiment No. 388, subject 0. E. S.: 
Kaoliang mush 


2,510.0 
1, 008. 

151.0 
1, 128. 

172.0 


1,969.4 

911.8 

16.6 

451.2 


67.5 
2.5 
1.5 


22.8 

3.1 

128.4 


432.7 

88.7 


17.6 


Apple sauce 


1.9 


Butter 


4.5 


Sirup 


676.8 
172.0 




Sugar 


















Total food consumed 


4, 969. 
163.0 


3, 349. 


71.5 
83.8 


154.3 

20.9 

133.4 


1,370.2 

42.6 

1,327.6 


24.0 


Feces 


15.7 


Amount utilized 




8.3 








Digestibility of entire ration (per cent). 


.... i 


86.5 


96.9 


34.6 




I 




Estimated digestibility of mush alone 
(per cent ) 






96.1 












Experiment No. 397, subject D. G. G.: 
Kaoliang mush 


2,831.0 
830.0 
175.0 

1, 266. 
108.0 


2,036.1 

756.5 

19.2 

506.4 


109.7 
1.9 
1.7 


26.3 
2.4 

148.8 


629.5 
67.8 


29.4 


Apple sauce 

Butter 


1.4 
5.3 


Sirup 


759.6 
108.0 




Sugar 


















Total food consumed 


5, 210. 
199.0 


3,318.2 


113.3 

110.3 

3.0 


177.5 

21.6 

155.9 


1,564.9 

51.2 

1,513.7 


36.1 


Feces 


15.9 


Amount utilized 




20.2 










Digestibility of entire ration (percent). 






2.6 


87.8 


96.7 


56.0 











Estimated digestibility of mush alone 
(per cent) 








95.7 














Experiment No. 398, subject A. J. H.: 
Kaoliang mush 


1,988.0 

653.0 

208.0 

253.0 

54.0 


1, 429. 8 

595.1 

22.9 

101.2 


77.0 
1.5 
2.1 


18.5 

1.9 

176.8 


442.0 
53.4 


20.7 


Apple sauce : 


1.1 


Butter 


6.2 


Sirup . 


151.8 
54.0 




Sugar 


















Total food consumed 


3, 156. 
131.0 


2, 149. 


80.6 

71.7 

8.9 


197.2 

17.4 

179.8 


701.2 

30.1 

671.1 


28. 


Feces 


11.8 


Amount utilized 




16.2 










Digestibility of entire ration (percent). 




11.0 


91.2 


95.7 


57.9 










Estimated digestibility of mush alone 
(per cent) 






7.3 




95.3 














Experiment No. 399, subject R. L. S.: 
Kaoliang mush 


2, 822. 

760.0 

341.0 

716.0 

40.0 


2, 029. 6 

692.7 

37.5 

286.4 


109.4 
1.7 
3.4 


26.2 

2.2 

289.9 


627.5 
62.1 




29.3 


Apple sauce 


1.3 


Butter 


10.2 


Sirup 


429.6 
40.0 




Sugar 


















Total food consumed 


4, 679. 
160.0 


3, 046. 2 


114.5 
86.4 
28.1 


318.3 

22.7 

295. 6 


1, 159. 2 

36.0 

1,123.2 


40.8 


Feces 


14.9 


Amount utilized 




25.9 










Digestibility of entire ration (per cent) . 






24.5 


92.9 


96.9 


63.5 










Estimated digestibility of mush alone 
(per cent) 






21.4 




96.7 















28 BULLETIN 470, l T . S. DEPARTMENT OF AGRICULTURE. 

Data of digestion experiments with kaoliang mush in a simple mixed diet — Continued. 





Weight. 


Water. 


Protein. 


Fat. 


Carbohy- 
drates. 


Ash. 


Experiment No. 400, subject 0. E. S.: 
Kaoliang mush 


Grams. 

2, 146. 
742.0 
198.0 

1,036.0 
192.0 


Grams. 
1,543.4 

676.2 
21.8 

414.4 


Grams. 

83.2 

1.7 

2.0 


Grams. 

20.0 

2.2 

168.3 


Grams. 

477.1 

60.6 


Grams. 
22. 


Apple sauce 


1.3 


Butter 


5.9 


Sirup 


621.6 
192.0 




Sugar 










1 




Total food consumed 


4,314.0 
154.0 


2, 655. 8 


86.9 

78.2 
8.7 


190.5 

26.1 

164.4 


1,351.3 

35.4 

1,315.9 


29.5 


Feces 


14.3 


Amount utilized 




15.2 










Digestibility of entire ration (per cent) . 






10.0 


86.3 


97.4 


51.5 










Estimated digestibility of mash alone 
(per cent) 






6.5 
29.3 




97.4 
399.1 




Average food consumed per subject 
per day 


1, 542. 


1,032.2 


71.3 


10.1 







Summary of digestion experiments with kaoliang mush in a simple mixed diet. 



Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates. 


Experi- 
ment No. 


Subject. 


Protein. 


Carbohy- 
drates. 


385 


D.G.G 

A. J.H 

R.L.S 

O.E.S 

D.G.G 


Per cent. 


Per cent . 
96.9 


398 

399 

400 


A. J.H 


Per cent . 

7.3 

21.4 

6.5 


Per cent. 
95. 3 


386 

387 

388 

397 


96. 6 
95. 6 

OA 1 


R.L.S 

O. E.S 

Average 


96.7 
97.4 




95.7 


4.4 


96.2 



The digestibility of the kaoliang protein was found by averaging 
the eight experiments to be only 4.4 per cent, although the carbo- 
hydrate from this source was 96.2 per cent digested; 28 grams of 
protein and 168 grams of carbohydrate per man per day were sup- 
plied by the kaoliang mush. As the subjects reported that they 
were in normal physical condition during these experiments, it seems 
reasonable to attribute the incomplete digestibility of the kaoliang 
protein to the structure of the grain rather than to the chemical 
nature of the protein molecule. In view of the lack of information, 
however, regarding the histology of kaoliang and the other grain 
sorghums, it is difficult at the present time to explain conclusively 
the differences found for the digestibility of the protein constituent 
of these cereals. 

SUMMARY OF DATA ON THE DIGESTIBILITY OF THE GRAIN-SORGHUM MUSHES. 

The results of the experiments with the sorghum mushes show that 
48.4 per cent, 48 per cent, 32.6 per cent, and 4.4 per cent of the 
cereal protein furnished by the rations containing dwarf kafir, 
feterita, dwarf milo, and kaoliang, respectively, are the estimated 
values for the digestibility of the protein constituent of the grains. 
Since these values were determined by as direct a method as is 
possible — 98 to 99 per cent of the total protein of the diet was ob- 



DIGESTIBILITY OF THE GRAIN SORGHUMS. 29 

tained from the grains — they may be considered to represent the 
digestibility of protein determined directly rather than estimated. 
The carbohydrate portion of the diet was as well assimilated as in the 
ordinary mixed diet, indicating that the very incomplete digest- 
ibility of protein was not due to faulty experimental methods. The 
diet proved to be entirely satisfying, at least for the three-day period, 
for the subjects reported that they were in normal physical condition 
throughout the experiments. 

Comparing the experiments in which mush was eaten with those 
in which sorghum gingerbread formed the major portion of the diet, 
it was found that an average of 41 grams of protein per man per day 
was supplied in the former and 35 grams in the latter series of ex- 
periments. The explanation of such a small consumption of protein 
lies in the fact that the grain sorghums contain too little protein to 
make it feasible to obtain, say, 100 grams of protein daily on a diet of 
this nature. The amounts of energy supplied by the mush and bread 
diets were 3,000 and 2,850 calories, respectively, an energy value in 
agreement with the standard dietary requirements. 

SUMMARY AND CONCLUSIONS. 

In the experiments in which the hard kafir bread was eaten with 
milk it was found that the cereal protein was 58 per cent digested, 
but very likely owing to the large amount of milk protein in the diet 
this value may be too high for the cereal protein alone. Comparing 
the results of all the other experiments reported in this paper, it may 
be seen that the average digestibility of the grain sorghums was found 
to vary from 46 to 48 per cent for the protein of dwarf kafir, 46 to 
48 per cent for that of feterita, 33 to 35 per cent for that of dwarf 
milo, and 4 to 20 per cent for that of kaoliang. The digestibility 
of the fat constituent of the grains, which is present in only small 
quantities, was considered relatively unimportant and consequently 
was not determined. The carbohydrate of all the sorghums was very 
completely utilized, the estimated average values for dwarf kafir 
being 98, 97, and 96 per cent, for feterita 98 and 98 per cent, for 
dwarf milo 97 and 98 per cent, and for kaoliang 96 and 96 per cent. 

Corn and wheat proteins were found to be somew hat less thoroughly 
available than is usually reported for these cereals ; the chief cause for 
this was probably the coarseness of the meals studied. The average 
digestibility of corn protein was found to be 55.4 per cent and that of 
wheat 74.4 per cent, while the carbohydrate constituents of these 
cereals were estimated to be 96.6 per cent and 95.9 percent digested, 
respectively. Since the experiments with all of the grains, however, 
were conducted under conditions as nearly uniform as possible, the 
results should be comparable. Hence it may be concluded that the 



30 BULLETIN 470, U. S. DEPARTMENT OF AGRICULTURE. 

protein of the grain sorghums is less digestible than that contained 
in either corn or wheat. 

The discussion so far has concerned the experimental data princi- 
pally from a technical standpoint, but the practical application of the 
results is certainly of equal interest. From the data here recorded 
and elsewhere available regarding the preparation of the sorghums 
for the table, it seems fair to conclude that these cereals are de- 
cidedly valuable as human food. They can be prepared for the table 
in palatable form, requiring, however, some special method of cook- 
ing to insure their being at their best. In preparing them it is most 
important to make certain of the absorption of water in such quan- 
tities that the particles of meal which are characteristically hard or 
flinty may be well softened. 

To many palates the grain sorghums more nearly resemble buck- 
wheat in flavor than they do corn or wheat. The flavor is quite 
generally regarded as agreeable, and the grains are conceded 'o be 
wholesome. Though their protein is less completely assimilated than 
that of corn or wheat, they are nevertheless, with the exception of 
kaoliang, a fairly good source of this nutrient. Furthermore, the 
sorghums are a good source of carbohydrate and furnish this im- 
portant food constituent in a form very completely available to the 
body. The use of the grain sorghums in general offers variety to the 
diet, and in regions where other cereals are not so successfully grown 
they may contribute materially to the supply of materials suitable as 
human food. 



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